Werner’s model

Figure 14. Alfred Werner s models of the enantiomorphs of an octahedral trisdidentate complex. (Reproduced with permission from reference 7, p 69. Copyright 1966 Springer-Verlag.)...

Werner s Model for the Structures of Complex Salts of Transition Metals... 

The Blomstrand-J0rgensen model suggested that the trisamine also should give two ions in aqueous solution, while the Werner model suggested that both the three amines and the three nitrite ions should be strongly bonded to the metal. This implied that the complex forms one molecular unit. And indeed, the electrical conductivity of the aqueous solution was found to be negligible. Werner s model was clearly the better ... 

The imprecise nature of Schrodinger s model was supported shortly afterwards by a principle proposed by Werner Heisenberg, in 1927. Heisenberg demonstrated that it is impossible to know both an electron s pathway and its exact location. Heisenberg s uncertainty principle is a mathematical relationship that shows that you can never know both the position and the momentum of an object beyond a certain measure of precision. 

Opposed to these three models in constitution as well as in configuration was Werner s regular tetrahedron, VII, which assumes four equivalent valence bonds instead of five valence bonds, not all of which are equal. 

In spite of the many modern techniques available to the chemist, the known chemistry of polynuclear cobalt (III) complexes is essentially that deduced by Werner 60 years ago. Since his work, no new polynuclear cobalt complexes have been prepared and characterized and no new reactions uncovered. Modem work in this area is being aimed at attaining a better understanding of the electronic structures inherent in polynuclear ions, which would be of value in a variety of active fields. The chemistry of polynuclear complexes is important in such new areas as synthetic oxygen carriers, electron transfer reactions, and transition metal catalysis. The fact that these new investigations are solidly based on Werner s pioneer investigations testifies to the genius with which he opened up a new area of coordination chemistry, with only the simple chemical techniques available to him. His work in the area of polynuclear cobalt(III) ammine complexes should continue to serve as a model of solid research for some time to come. 

The general approach used was to prepare complexes which could exist in isomeric forms, the number of isomers expected depending upon the assumed model. So great was Werner s ingenuity and skill that many of the isomeric complexes now known can be considered to be some variation of those isolated by him. It is significant that optical activity played an... 

J0rgensen s chain theory for some cobalt(III) complexes (top), compared with the Werner representations (bottom). Werner s representation for [CoC13(NH3)3] fits the nonelectrolyte behaviour seen experimentally, unlike the Jprgensen model. 

Messer T, Schmauss M, Spevakne-Goeroecs T, Kungel M, Ebrecht M, Werner C, Modell S. Clinical use of aripiprazole in patients with schizophrenia a real-life setting results from the German Postmarketing Surveillance Study. World J Biol Psychiatry 2010 11 231-8. 

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